OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Tecumseh / Kirby Engines Engine flush post water in sump

Hi, I have a 3.5HP "Vinaro" brand mower with a tecumseh engine (similar to the B&S sprint engine). It's been left in the open without a dipstick and rain/hosing has filled it up with water. The oil is like a light chocolate milk drink. I've flushed it 4 times with engine oil and once with kerosine but it is still discoloured and milky. What should I do to clear the mess up properly? Is it safe to run with any water remaining in the sump. I think any water might bend the rod or damage the engine if I start it with any water remaining but how can I get it all out. Any ideas?

Ordinary oil does not mix with water, and no amount of flushing with oil will remove the water. I suggest you drain the sump and put in a small amount of soluble oil, also known as cutting oil or cutting tool coolant. Do not dilute the cutting oil with water of course - put it into the sump as normal-looking oil. Put in just a couple of hundred millilitres, remove the spark plug, and pull the engine over briskly several times with the starter cord. Drain the cutting oil and see if it has become milky. If it has, put in another couple of hundred ml, and repeat until it comes out clear, not milky. When you reach that point it is time to fill with engine oil, start the engine, run it at no load for about 30 seconds to a maximum of one minute, and drain the oil. If it is completely clear, you can re-fill with more clean oil and put the engine back to work.

Thanks (again) Grumpy. I'll get some oil tomorrow and give it a go. Some pictures too.

Thanks sparker - this will be a much better thread if the process is traced and documented all the way to the cure. People can then have confidence in the results.

Niether Supacheap nor McGinns had any soluble oil. The latter had sold their last lot the day before. Hey, this is Mackay! Anyway, I had left the mower draining it's old oil overnight so I had another refill of its sump today and had a look at how its colour was when it was draining. It didn't seem too bad so I decided to top it up and see how it went. There were a lot of other sundry problems with the carby (water had got into it too)and so on but the mower is now running fine. Tecumseh engines/carby's seem to be very tough and easy starters.



Sorry about the lack of pictures. The top one is the one that is now fixed (more or less). The second one is the next one with an oil/water problem. This one is from the same household and it has had the same maltreatment. I'll do a picture job on it. Note the chinese safety boot in the bottom picture.

In my limited experience with them, Tecumseh engines are mechanically robust and durable, but tend to have terrible carburetors, which spoil the whole picture and make you want to kick them rather than fix them.

Because your last batch of oil had sat overnight in the engine before you drained it, you should not feel too confident that you got all the water out. Soluble oil forms a durable emulsion with water, but engine oil does not, so what looks like a chocolate milkshake right after you've run it, might turn back into oil with a pool of water underneath it, by morning.

I suggest you finish off the job on that first mower by running it for 10 minutes or so, then draining the oil immediately into a clean container. If it is clean not milky, you can put it back into the engine and feel fairly confident. If it looks milky, you still need to get that soluble oil. You need to get it anyway, to deal with the second mower without using up many litres of engine oil along the way.

This came from an old briggs & stratton edger. This was a result of a leaky oil-seal where the edger sat in a yard on a lean in wet weather. I drained the oil into a clear jar and although I knew there was water in it ,I didn't relize how much till the next morning. Cheers.

Thanks Rob, that illustrates how the water settles out overnight. It will stay in suspension in soluble oil for months, even if there is more water than soluble oil.

Ok here is a sample of the oil after running for 10 minutes. The rest is on my garage floor after knocking the container over. It doesn't seem to be milky but has a very low viscosity. It sloshes about like water.
I don't think I'll put this back in to the mower.
Yesterday I went to another hardware shop (Porters) and another motor vehicle parts shop. I walked out of the MV shop after waiting too long and porters had a little section there for "Cutting oil" but guess what - there was no stock in that section. I think I'll get it off Ebay. I tried shopping locally and it was a dead loss.

The low viscosity of warm oil is normal, sparker. That is why you always warm up the engine before oil changes. I do not see any signs of water in that oil, just carbon. Most likely the bottom of the oil sump is pretty dirty, and your series of oil changes didn't affect that much. Does the engine produce any blue exhaust smoke? If not, and if you can feel clear, but not intense, compressions on the starter cord, chances are all is well to keep using the engine.

I wouldn't put that oil back in the engine either. The only time I re-use black oil is when I know for certain that it has only run a short time (up to perhaps 8 hours in a worn engine), and then I use it for running-in oil (the first two hours after fitting new rings). Then I change it, and if it is a Honda at least, it will stay clear for quite a few hours. However if you have black crud in the bottom of the sump, your oil will always get dirty fairly quickly just by picking up old garbage.